feat(signatures): Initial signature support

Summary:
- Draft Store extensions can now implement `prepareNewDraft` to have an opportunity to change a draft before it's displayed for the first time.

- When composers are torn down, they delete their draft if it is still pristine. This makes the behavior of closing unedited popout drafts the same as leaving unedited inline drafts.

- The DraftStoreProxy keeps the initial body of the draft *if* it started in a pristine state. This means "is the body empty" is just a simple == check, and it takes into account anything added to the body by extensions.

- Calling Actions.destroyDraft doesn't blow up anymore if the draft session can't be found. This was a bug and meant that you couldn't destroy drafts which hadn't been previously edited, and also meant that bad things(tm) happened when you called destroyDraft twice, which seemed like overkill.

- DestroyDraft task now exits gracefully when the draft cannot be found.

You can test this feature by adding the following to your config.cson:

```
  signatures:
     NAMESPACEID: "<br/><br/><div id=\"Signature\"><div id=\"divtagdefaultwrapper\" style=\"font-size:12pt; color:#000000; background-color:#FFFFFF; font-family:Calibri,Arial,Helvetica,sans-serif\"><p></p><table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"450\" style=\"font-family:'Times New Roman'; table-layout:fixed\"><tbody><tr><td class=\"logo-td\" align=\"left\" valign=\"top\" width=\"76\"><p style=\"margin-bottom:10px; margin-right:10px; font-family:Helvetica,Arial,sans-serif; font-size:14px; line-height:16px\"><a href=\"http://www.nylas.com/\" class=\"clink logo-container\" style=\"text-decoration:none\"><img alt=\"Nylas\" border=\"0\" class=\"sig-logo\" height=\"80\" width=\"66\" style=\"-webkit-user-select: none;\" src=\"https://s3-us-west-2.amazonaws.com/nylas-static-assets/nylas-email-signature.png\"></a></p><p class=\"social-list\" style=\"font-size:0px; line-height:0; font-family:Helvetica,Arial,sans-serif\"></p></td><td align=\"left\" valign=\"top\" nowrap=\"nowrap\" class=\"spacer-td\" width=\"16\" style=\"border-left-width:2px; border-left-style:solid; border-left-color:rgb(30,162,162)\"><img width=\"10\" style=\"-webkit-user-select: none;\" src=\"https://s3.amazonaws.com/htmlsig-assets/spacer.gif\"></td><td align=\"left\" valign=\"top\" nowrap=\"nowrap\" class=\"content-td\" width=\"368\"><div class=\"content-pad\"><p style=\"font-family:Helvetica,Arial,sans-serif; font-size:14px; line-height:16px; color:rgb(33,33,33); margin-bottom:10px\"><span class=\"txt signature_name-target sig-hide\" style=\"font-weight:bold; display:inline\">Gleb Polyakov</span>&nbsp;<span class=\"email-sep break\" style=\"display:inline\"><br></span><a class=\"link email signature_email-target sig-hide\" href=\"mailto:gleb@nylas.com\" style=\"color:rgb(30,162,162); text-decoration:none; display:inline\">gleb@nylas.com</a><span class=\"signature_email-sep sep\" style=\"display:inline\">&nbsp;/&nbsp;</span><span class=\"txt signature_mobilephone-target sig-hide\" style=\"display:inline\">404-786-4100</span></p><p style=\"font-family:Helvetica,Arial,sans-serif; font-size:14px; line-height:16px; margin-bottom:10px\"><span class=\"txt signature_companyname-target sig-hide\" style=\"font-weight:bold; color:rgb(33,33,33); display:inline\">Nylas</span>&nbsp;<span class=\"company-sep break\" style=\"display:inline\"><br></span><span class=\"address-sep break\"></span><span class=\"address2-sep break\"></span><span class=\"website-sep break\"></span><a class=\"link signature_website-target sig-hide\" href=\"http://www.nylas.com/\" style=\"color:rgb(30,162,162); text-decoration:none; display:inline\">http://www.nylas.com</a></p></div></td></tr><tr><td colspan=\"3\"></td></tr><tr><td colspan=\"3\"></td></tr><tr><td colspan=\"3\"><p class=\"txt signature_disclaimer-target\" style=\"font-family:Helvetica,Arial,sans-serif; color:rgb(33,33,33); font-size:9px; line-height:12px; margin-top:10px\"></p></td></tr></tbody></table><p></p></div></div>"
```

specs for draft store extension hooks, some draft store refactoring

Test Plan: Run a few new specs that make sure extensions are run

Reviewers: evan

Reviewed By: evan

Differential Revision: https://phab.nylas.com/D1741

internal_packages/composer-signature/lib/draft-extension.coffee

@@ -0,0 +1,14 @@
+{DraftStoreExtension, NamespaceStore} = require 'nylas-exports'
+
+class SignatureDraftStoreExtension extends DraftStoreExtension
+  @prepareNewDraft: (draft) ->
+    namespaceId = NamespaceStore.current().id
+    signature = atom.config.get("signatures.#{namespaceId}")
+    return unless signature
+
+    insertionPoint = draft.body.indexOf('<blockquote')
+    if insertionPoint is -1
+      insertionPoint = draft.body.length
+    draft.body = draft.body.substr(0, insertionPoint-1) + signature + draft.body.substr(insertionPoint)
+
+module.exports = SignatureDraftStoreExtension

internal_packages/composer-signature/lib/main.coffee

@@ -0,0 +1,11 @@
+{ComponentRegistry, DraftStore} = require 'nylas-exports'
+Extension = require './draft-extension'
+
+module.exports =
+  activate: (@state={}) ->
+    DraftStore.registerExtension(Extension)
+
+  deactivate: ->
+    DraftStore.unregisterExtension(Extension)
+
+  serialize: -> @state

internal_packages/composer-signature/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "composer-signature",
+  "version": "0.1.0",
+  "main": "./lib/main",
+  "description": "A small extension to the draft store that implements signatures",
+  "license": "Proprietary",
+  "private": true,
+  "engines": {
+    "atom": "*"
+  },
+  "windowTypes": {
+    "composer": true
+  },
+  "dependencies": {
+  }
+}

internal_packages/composer-signature/spec/draft-extension-spec.coffee

@@ -0,0 +1,36 @@
+{Message} = require 'nylas-exports'
+
+SignatureDraftStoreExtension = require '../lib/draft-extension'
+
+describe "SignatureDraftStoreExtension", ->
+  describe "prepareNewDraft", ->
+    describe "when a signature is defined", ->
+      beforeEach ->
+        @signature = "<div id='signature'>This is my signature.</div>"
+        spyOn(atom.config, 'get').andCallFake =>
+          @signature
+
+      it "should insert the signature at the end of the message or before the first blockquote", ->
+        a = new Message
+          draft: true
+          body: 'This is a test! <blockquote>Hello world</blockquote>'
+        b = new Message
+          draft: true
+          body: 'This is a another test.'
+
+        SignatureDraftStoreExtension.prepareNewDraft(a)
+        expect(a.body).toEqual("This is a test!<div id='signature'>This is my signature.</div><blockquote>Hello world</blockquote>")
+        SignatureDraftStoreExtension.prepareNewDraft(b)
+        expect(b.body).toEqual("This is a another test<div id='signature'>This is my signature.</div>")
+
+    describe "when a signature is not defined", ->
+      beforeEach ->
+        spyOn(atom.config, 'get').andCallFake ->
+          null
+
+      it "should not do anything", ->
+        a = new Message
+          draft: true
+          body: 'This is a test! <blockquote>Hello world</blockquote>'
+        SignatureDraftStoreExtension.prepareNewDraft(a)
+        expect(a.body).toEqual('This is a test! <blockquote>Hello world</blockquote>')

internal_packages/composer/lib/composer-view.cjsx

@@ -71,7 +71,7 @@ class ComposerView extends React.Component
       'composer:show-and-focus-cc': @_showAndFocusCc
       'composer:focus-to': => @focus "textFieldTo"
       'composer:send-message': => @_sendDraft()
-      'composer:delete-empty-draft': => @_deleteEmptyDraft()
+      'composer:delete-empty-draft': => @_deleteDraftIfEmpty()
       "core:undo": @undo
       "core:redo": @redo
     }
@@ -83,6 +83,7 @@ class ComposerView extends React.Component
   componentWillUnmount: =>
     @_unmounted = true # rarf
     @_teardownForDraft()
+    @_deleteDraftIfEmpty()
     @_uploadUnlisten() if @_uploadUnlisten
     @_draftStoreUnlisten() if @_draftStoreUnlisten
     @_keymapUnlisten.dispose() if @_keymapUnlisten
@@ -518,16 +519,11 @@ class ComposerView extends React.Component
       })
       return
 
+    bodyIsEmpty = draft.body is @_proxy.draftPristineBody()
     body = QuotedHTMLParser.removeQuotedHTML(draft.body.toLowerCase().trim())
     forwarded = Utils.isForwardedMessage(draft)
     hasAttachment = (draft.files ? []).length > 0
 
-    # We insert empty br tags before quoted text.
-    # Our quoted text parser adds additional document elements
-    onlyHasBr = (/^(<br[^>]*>)+$/gi).test(body)
-    onlyHasDoc = (/^<head><\/head><body><br><br><\/body>$/i).test(body)
-    bodyIsEmpty = body.length is 0 or onlyHasBr or onlyHasDoc
-
     warnings = []
 
     if draft.subject.length is 0
@@ -642,7 +638,7 @@ class ComposerView extends React.Component
 
     @undoManager.saveToHistory(historyItem)
 
-  _deleteEmptyDraft: =>
+  _deleteDraftIfEmpty: =>
     return unless @_proxy
     if @_proxy.draft().pristine then Actions.destroyDraft(@props.localId)
 

internal_packages/composer/spec/composer-view-spec.cjsx

@@ -47,6 +47,7 @@ passThroughStub = (props={}) ->
 draftStoreProxyStub = (localId, returnedDraft) ->
   listen: -> ->
   draft: -> (returnedDraft ? new Message(draft: true))
+  draftPristineBody: -> null
   draftLocalId: localId
   cleanup: ->
   changes:
@@ -335,21 +336,17 @@ describe "populated composer", ->
       expect(dialogArgs.buttons).toEqual ['Edit Message']
 
     describe "empty body warning", ->
-      it "warns if the body of the email is empty", ->
-        useDraft.call @, to: [u1], body: ""
-        makeComposer.call(@)
-        @composer._sendDraft()
-        expect(Actions.sendDraft).not.toHaveBeenCalled()
-        expect(@dialog.showMessageBox).toHaveBeenCalled()
-        dialogArgs = @dialog.showMessageBox.mostRecentCall.args[1]
-        expect(dialogArgs.buttons).toEqual ['Cancel', 'Send Anyway']
+      it "warns if the body of the email is still the pristine body", ->
+        pristineBody = "<head></head><body><br><br></body>"
 
-      it "warns if the body of the email is all quoted text", ->
         useDraft.call @,
           to: [u1]
           subject: "Hello World"
-          body: "<head></head><body><br><br></body>"
+          body: pristineBody
         makeComposer.call(@)
+
+        spyOn(@composer._proxy, 'draftPristineBody').andCallFake -> pristineBody
+
         @composer._sendDraft()
         expect(Actions.sendDraft).not.toHaveBeenCalled()
         expect(@dialog.showMessageBox).toHaveBeenCalled()
@@ -365,16 +362,6 @@ describe "populated composer", ->
         @composer._sendDraft()
         expect(Actions.sendDraft).toHaveBeenCalled()
 
-      it "does not warn if the user has typed a single character in their reply", ->
-        useDraft.call @,
-          to: [u1]
-          subject: "Hello World"
-          body: "1<br><br><blockquote class='gmail_quote'>This is my quoted text!</blockquote>"
-        makeComposer.call(@)
-        @composer._sendDraft()
-        expect(Actions.sendDraft).toHaveBeenCalled()
-        expect(@dialog.showMessageBox).not.toHaveBeenCalled()
-
       it "does not warn if the user has attached a file", ->
         useDraft.call @,
           to: [u1]

spec-nylas/stores/draft-store-spec.coffee

@@ -5,6 +5,7 @@ ModelQuery = require '../../src/flux/models/query'
 NamespaceStore = require '../../src/flux/stores/namespace-store'
 DatabaseStore = require '../../src/flux/stores/database-store'
 DraftStore = require '../../src/flux/stores/draft-store'
+DraftStoreExtension = require '../../src/flux/stores/draft-store-extension'
 TaskQueue = require '../../src/flux/stores/task-queue'
 SendDraftTask = require '../../src/flux/tasks/send-draft'
 DestroyDraftTask = require '../../src/flux/tasks/destroy-draft'
@@ -19,7 +20,14 @@ msgFromMe = null
 msgWithReplyTo = null
 fakeMessages = null
 
+class TestExtension extends DraftStoreExtension
+  @prepareNewDraft: (draft) ->
+    draft.body = "Edited by TestExtension!" + draft.body
+
 describe "DraftStore", ->
+  beforeEach ->
+    spyOn(atom, 'newWindow').andCallFake ->
+
   describe "creating drafts", ->
     beforeEach ->
       fakeThread = new Thread
@@ -274,6 +282,19 @@ describe "DraftStore", ->
         , (model) ->
           expect(model.subject).toEqual("Fwd: Fake subject")
 
+      describe "extensions", ->
+        beforeEach ->
+          DraftStore.registerExtension(TestExtension)
+        afterEach ->
+          DraftStore.unregisterExtension(TestExtension)
+
+        it "should give extensions a chance to customize the draft via ext.prepareNewDraft", ->
+          @_callNewMessageWithContext {threadId: fakeThread.id}
+          , (thread, message) ->
+            {}
+          , (model) ->
+            expect(model.body.indexOf("Edited by TestExtension!")).toBe(0)
+
       describe "context", ->
         it "should accept `thread` or look up a thread when given `threadId`", ->
           @_callNewMessageWithContext {thread: fakeThread}
@@ -430,11 +451,10 @@ describe "DraftStore", ->
       DraftStore._onDestroyDraft('abc')
       expect(@draftReset).toHaveBeenCalled()
 
-    it "should throw if the draft session is not in the window", ->
+    it "should not throw if the draft session is not in the window", ->
       expect ->
         DraftStore._onDestroyDraft('other')
-      .toThrow()
-      expect(@draftReset).not.toHaveBeenCalled()
+      .not.toThrow()
 
     it "should queue a destroy draft task", ->
       DraftStore._onDestroyDraft('abc')
@@ -603,6 +623,20 @@ describe "DraftStore", ->
       expect(@draftCleanup).toHaveBeenCalled
 
   describe "mailto handling", ->
+    describe "extensions", ->
+      beforeEach ->
+        DraftStore.registerExtension(TestExtension)
+      afterEach ->
+        DraftStore.unregisterExtension(TestExtension)
+
+      it "should give extensions a chance to customize the draft via ext.prepareNewDraft", ->
+        received = null
+        spyOn(DatabaseStore, 'persistModel').andCallFake (draft) ->
+          received = draft
+          Promise.resolve()
+        DraftStore._onHandleMailtoLink('mailto:bengotow@gmail.com')
+        expect(received.body.indexOf("Edited by TestExtension!")).toBe(0)
+
     it "should correctly instantiate drafts for a wide range of mailto URLs", ->
       received = null
       spyOn(DatabaseStore, 'persistModel').andCallFake (draft) ->

src/flux/stores/draft-store-extension.coffee

@@ -44,7 +44,21 @@ class DraftStoreExtension
     []
 
   ###
-  Public: Override onMouseUp in your DraftStoreExtension subclass to transform
+  Public: Override prepareNewDraft to modify a brand new draft before it is displayed
+  in a composer. This is one of the only places in the application where it's safe
+  to modify the draft object you're given directly to add participants to the draft,
+  add a signature, etc.
+
+  By default, new drafts are considered `pristine`. If the user leaves the composer
+  without making any changes, the draft is discarded. If your extension populates
+  the draft in a way that makes it "populated" in a valuable way, you should set
+  `draft.pristine = false` so the draft saves, even if no further changes are made.
+  ###
+  @prepareNewDraft: (draft) ->
+    return
+
+  ###
+  Public: Override finalizeSessionBeforeSending in your DraftStoreExtension subclass to transform
   the {DraftStoreProxy} editing session just before the draft is sent. This method
   gives you an opportunity to make any final substitutions or changes after any
   {::warningsForSending} have been displayed.

src/flux/stores/draft-store-proxy.coffee

@@ -88,27 +88,36 @@ class DraftStoreProxy
     @listenTo DraftStore, @_onDraftChanged
     @listenTo Actions.didSwapModel, @_onDraftSwapped
 
+    @_draft = false
+    @_draftPristineBody = null
+
     @changes = new DraftChangeSet @draftLocalId, =>
       if !@_draft
         throw new Error("DraftChangeSet was modified before the draft was prepared.")
       @trigger()
 
     if draft
-      @_draft = draft
+      @_setDraft(draft)
       @_draftPromise = Promise.resolve(@)
-    else
-      @_draft = false
-      @_draftPromise = null
 
     @prepare().catch (error) ->
       console.error(error)
       console.error(error.stack)
       throw new Error("DraftStoreProxy prepare() failed with error #{error.toString()}.")
 
+  # Public: Returns the draft object with the latest changes applied.
+  #
   draft: ->
     @changes.applyToModel(@_draft)
     @_draft
 
+  # Public: Returns the initial body of the draft when it was pristine, or null if the
+  # draft was never pristine in this editing session. Useful for determining if the
+  # body is still in an unchanged / empty state.
+  #
+  draftPristineBody: ->
+    @_draftPristineBody
+
   prepare: ->
     @_draftPromise ?= new Promise (resolve, reject) =>
       DatabaseStore = require './database-store'
@@ -127,6 +136,12 @@ class DraftStoreProxy
   _setDraft: (draft) ->
     if !draft.body?
       throw new Error("DraftStoreProxy._setDraft - new draft has no body!")
+
+    # We keep track of the draft's initial body if it's pristine when the editing
+    # session begins. This initial value powers things like "are you sure you want
+    # to send with an empty body?"
+    if draft.pristine
+      @_draftPristineBody = draft.body
     @_draft = draft
     @trigger()
 

src/flux/stores/draft-store.coffee

@@ -200,6 +200,26 @@ class DraftStore
     @_newMessageWithContext context, (thread, message) ->
       forwardMessage: message
 
+  _finalizeAndPersistNewMessage: (draft) =>
+    # Give extensions an opportunity to perform additional setup to the draft
+    for extension in @_extensions
+      continue unless extension.prepareNewDraft
+      extension.prepareNewDraft(draft)
+
+    # Normally we'd allow the DatabaseStore to create a localId, wait for it to
+    # commit a LocalLink and resolve, etc. but it's faster to create one now.
+    draftLocalId = generateTempId()
+
+    # Optimistically create a draft session and hand it the draft so that it
+    # doesn't need to do a query for it a second from now when the composer wants it.
+    @_draftSessions[draftLocalId] = new DraftStoreProxy(draftLocalId, draft)
+
+    Promise.all([
+      DatabaseStore.bindToLocalId(draft, draftLocalId)
+      DatabaseStore.persistModel(draft)
+    ]).then =>
+      return Promise.resolve({draftLocalId})
+
   _newMessageWithContext: ({thread, threadId, message, messageId, popout}, attributesCallback) =>
     return unless NamespaceStore.current()
 
@@ -290,16 +310,7 @@ class DraftStore
         threadId: thread.id
         namespaceId: thread.namespaceId
 
-      # Normally we'd allow the DatabaseStore to create a localId, wait for it to
-      # commit a LocalLink and resolve, etc. but it's faster to create one now.
-      draftLocalId = generateTempId()
-
-      # Optimistically create a draft session and hand it the draft so that it
-      # doesn't need to do a query for it a second from now when the composer wants it.
-      @_draftSessions[draftLocalId] = new DraftStoreProxy(draftLocalId, draft)
-
-      DatabaseStore.bindToLocalId(draft, draftLocalId)
-      DatabaseStore.persistModel(draft).then =>
+      @_finalizeAndPersistNewMessage(draft).then ({draftLocalId}) =>
         Actions.composePopoutDraft(draftLocalId) if popout
 
 
@@ -323,10 +334,8 @@ class DraftStore
       pristine: true
       namespaceId: namespace.id
 
-    DatabaseStore.persistModel(draft).then =>
-      DatabaseStore.localIdForModel(draft).then (draftLocalId, options={}) =>
-        options.newDraft = true
-        @_onPopoutDraftLocalId(draftLocalId, options)
+    @_finalizeAndPersistNewMessage(draft).then ({draftLocalId}) =>
+      @_onPopoutDraftLocalId(draftLocalId, {newDraft: true})
 
   _onPopoutDraftLocalId: (draftLocalId, options = {}) =>
     return unless NamespaceStore.current()
@@ -368,23 +377,20 @@ class DraftStore
       if query[attr]
         draft[attr] = ContactStore.parseContactsInString(query[attr])
 
-    DatabaseStore.persistModel(draft).then =>
-      DatabaseStore.localIdForModel(draft).then(@_onPopoutDraftLocalId)
+    @_finalizeAndPersistNewMessage(draft).then ({draftLocalId}) =>
+      @_onPopoutDraftLocalId(draftLocalId)
 
   _onDestroyDraft: (draftLocalId) =>
     session = @_draftSessions[draftLocalId]
 
-    if not session
-      throw new Error("Couldn't find the draft session in the current window")
-
     # Immediately reset any pending changes so no saves occur
-    session.changes.reset()
+    if session
+      session.changes.reset()
+      @_doneWithSession(session)
 
     # Queue the task to destroy the draft
     Actions.queueTask(new DestroyDraftTask(draftLocalId))
 
-    @_doneWithSession(session)
-
     atom.close() if @_isPopout()
 
   # The user request to send the draft

src/flux/tasks/destroy-draft.coffee

@@ -26,7 +26,7 @@ class DestroyDraftTask extends Task
       return Promise.reject(new Error("Attempt to call DestroyDraftTask.performLocal without @draftLocalId"))
 
     DatabaseStore.findByLocalId(Message, @draftLocalId).then (draft) =>
-      return resolve() unless draft
+      return Promise.resolve() unless draft
       @draft = draft
       DatabaseStore.unpersistModel(draft)